Objective:
To study how K enters the berry and in what tissues it accumulates. To determine what is the sensitive phenological stage that is responsive to K. To study the influence of K on sugar translocation. To determine if K has effects on expression of genes in source and sink organs. To study applied aspects of the responses to K at the vineyard level.

Approach:
A combination of practical vineyard experiments evaluating the responses of grapes to potassium potassium applications including rates of maturation, internal quality, and control of preharvest and postharvest plant pathogens, combined with laboratory experiments evaluating the entry and spatial distribution of potassium within berries, gene expression by microarray analysis using the Nimblegen Grape array MD X 12 platform, and translocation of sugars.